In a complementary metal-oxide-semiconductor (CMOS) field effect transistor (FET), or MOSFET, active regions include a drain, a source, a channel region connected between the drain and the source, and a gate on top of the channel to control the on and off state of the channel region. When the gate voltage is more than a threshold voltage, a conductive channel is established between the drain and the source. As a result, electrons or holes are allowed to move between the drain and source. When the gate voltage is less than the threshold voltage, the channel is ideally cut off and no electrons or holes are flowing between the drain and the source.
In some circumstances, the performance of a semiconductor device such as a MOSFET is affected by the size of the transistor. The larger the transistor, the better the performance of the MOSFET. However, increasing the size of the transistor is contrary to demand in the industry for smaller semiconductor devices and results in an area penalty.
Corresponding numerals and symbols in the different figures generally refer to corresponding parts unless otherwise indicated. The figures are drawn to clearly illustrate the relevant aspects of the various embodiments and are not necessarily drawn to scale.